Solid state lighting such as LED lighting is becoming increasingly popular because of the energy efficient nature of such lighting as well as the lifetime of such lighting. A further advantage of solid state lighting is that the solid state lighting devices may have a configurable luminous output with short response times to configuration changes. This has led to the advent of intelligent luminaires including solid state lighting devices that further include one or more sensors and/or controllers for configuring the luminous output of the solid state lighting devices, e.g. dimming level, colour temperature and/or colour point of the solid state lighting devices.
In order to ensure an extended lifetime and desired luminous output of the solid state lighting devices, the solid state lighting devices, e.g. LEDs, are typically mounted or otherwise thermally connected to a heatsink, which absorbs heat generated by the solid state lighting devices and transfers this heat to its surroundings. To this end, such a heatsink typically has a large surface area, often provided by a plurality of fins of a heat conductive material such as a metal, metal alloy or thermal plastic, in order to ensure a high rate of heat transfer between the heatsink and its surroundings. In this manner, the heatsink can effectively maintain the operating temperature of the solid state lighting devices below a critical temperature, at or above which the solid state lighting devices may exhibit a reduced lifetime and/or degradation of optical performance. An example of a solid state lighting device including a device-scaled stamped heatsink with a base portion and multiple segments or side-walls projecting outward from the base portion is disclosed in U.S. Pat. No. 8,362,509 B2.
Typically, the one or more sensors and/or controllers are also mounted on the heatsink, e.g. in a peripheral area of the heatsink. Consequently, the one or more sensors and/or controllers are subjected to the heat from the solid state lighting devices absorbed by the heatsink. This can cause problems, for example because the heat generated by the one or more sensors and/or controllers cannot be effectively dissipated by the heatsink due to a negligible temperature gradient between the one or more sensors and/or controllers and the heatsink or due to a heatsink having a higher temperature than the one or more sensors and/or controllers. This can cause overheating of the one or more sensors and/or controllers, which may lead to premature failure of such components. To avoid such problems, the one or more sensors and/or controllers may be mounted external to the heatsink, i.e. separate therefrom, but this typically leads to bulky and/or aesthetically unsatisfactory luminaires.